It's a bit arbitrary, but you have to draw the line somewhere for where "human" begins. IIRC, 50k BC is around the time of Mitochondrial Eve, which seems a decent place.

Mitochondrial Eve is estimated to have lived around 200,000 years ago,[2] most likely in East Africa,[3] when Homo sapiens sapiens (anatomically modern humans) were developing as a population distinct from other human sub-species.

That's zero people plus or minus a few million. The margin of error is bigger than the population.

A lot of them were hiding in boxes with their cats and couldn't be counted by the enumerator without breaking and entering, so he or she put down a number based on the volume of the box and the amount of arguing and meowing coming from in the box.

While searching through Census records, I found that one person Charles G. Lewis, 18, was absent from the home at the time of enumeration. As a result, a whole new family, the Gabsent family, was accidentally created by a careless transcriber. A household of Old American WASPs in another census was turned into Italians by careless reading. As any Fortean knows, mysterious people pop into and out of existence constantly.

Since census-records are the basis for entitlements, there is a lot of political shenanigans as well, with conservatives denying the existence of possibly millions of Americans. The number of Muslims in America ranges from 1.5 million (if counted by Jews, B'nai B'rith) to 12 million (if counted by Muslims at the American Muslim Association or something like). That's a gap of over 10 million people, many of them members of the Ali Gabsent family. Republicans are not content to deny government services to people. They also try to deny people to government services.

This teaches us to be skeptical of statistics and numbers generally. Even with good faith and best practices, the population of the USA is only known to three, perhaps two, significant digits You could lose or gain a few small states without anybody noticing or caring. For example, when President Obama "accidentally" claimed there were 54 states HE MAY HAVE BEEN INADVERTANTLY LETTING THE CAT OUT OF THE BAG.

Personally I suspect that Obama has several states in reserve just in case the Election doesn't go his way.

Why, for example, is there a North Dakota and and a South Dakota? Why? Why? Do you even need one? Don't be surprise if East Dakota goes Democratic on Election Day. On the other hand, the Republicans are even worse. Don't be surprised if California disappears mysteriously, only to be won by the Republicans with 18,182 votes when it returns.

The world is full of Brigadoons, pockets of reality that float around and occasionally appear long enough to play nasty practical jokes on people.

Negative people are everywhere. Don't be fooled into thinking that the numbers are carved in stainless steel.

Has anyone really been far even as decided to use even go want to do look more like?

You've got to be kidding me. I've been further even more decided to use even go need to do look more as anyone can. Can you really be far even as decided half as much to use go wish for that? My guess is that when one really been far even as decided once to use even go want, it is then that he has really been far even as decided to use even go want to do look more like. It's just common sense.

At the pace earth resources are being consumed and depleted with any regard for future generations, that will take care of itself relatively soon.

Yeah, but wouldn't it be nice if politicians acted like grownups and initiated a serious discussion with the public about how we can make choices that transition to a sustainable population level in the least painful way possible before the enviro-economy makes those decisions for us, catastrophically?